Display device

ABSTRACT

According to one embodiment, a display device includes a first substrate, a second substrate opposing the first substrate, a wiring substrate connected to the first substrate, a cover member located on an opposite side to the first substrate so as to interpose the second substrate therebetween and a conductive layer maintained at a predetermined potential, and the first substrate includes an extension portion extending further from the second substrate, the wiring substrate is connected to the extension portion, the cover member includes a first surface opposing the extension portion, and the conductive layer overlaps the extension portion in plan view.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/161,619, filed on Oct. 16, 2018, which application is based upon andclaims the benefit of priority from Japanese Patent Application No.2017-203819, filed Oct. 20, 2017, the entire contents of which areincorporated herein by reference.

FIELD

Embodiments described herein relate generally to a display device.

BACKGROUND

Display devices such as liquid crystal display devices and the likecomprise a plurality of scanning lines and signal lines. The scanninglines and signal lines are electrically connected to a driver forcontrolling display operation, and the like. In some cases, the driveris provided on the display panel. In such a display device, when, forexample, high voltage is applied as a noise which comes from theoutside, the operation of the driver is sometimes adversely influenced.

SUMMARY

The present application relates generally to a display device.

According to an embodiment, a display device includes a first substrate,a second substrate opposing the first substrate, a wiring substrateconnected to the first substrate, a cover member located on an oppositeside to the first substrate so as to interpose the second substratetherebetween and a conductive layer maintained at a predeterminedpotential, and the first substrate includes an extension portionextending further from the second substrate, the wiring substrate isconnected to the extension portion, the cover member includes a firstsurface opposing the extension portion, and the conductive layeroverlaps the extension portion in plan view.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross section schematically showing a display device 1 ofthis embodiment.

FIG. 2 is an enlarged view of a vicinity of a wiring substrate 31 shownin FIG. 1.

FIG. 3 is a plan view showing a configuration example of the displaydevice 1.

FIG. 4 is a plan view showing a configuration example of a pixel PXshown in

FIG. 3.

FIG. 5 is a plan view showing a configuration example of a sensor SSprovided in the display device 1.

FIG. 6 is a perspective view showing an appearance of the display device1.

FIG. 7 is a perspective view showing another example of the appearanceof the display device 1.

FIG. 8 is a plan view showing a first modified example of the displaydevice 1.

FIG. 9 is a perspective view showing an appearance of the display device1 of the first modified example.

FIG. 10 is a plan view showing a second modified example of the displaydevice 1.

FIG. 11 is a perspective view showing an appearance of the displaydevice 1 of the second modified example.

FIG. 12 is a plan view showing a third modified example of the displaydevice 1.

FIG. 13 is a perspective view showing an appearance of the displaydevice 1 of the third modified example.

FIG. 14 is a plan view showing a fourth modified example of the displaydevice 1.

FIG. 15 is a plan view showing a fifth modified example of the displaydevice 1.

FIG. 16 is a plan view showing a sixth modified example of the displaydevice 1.

FIG. 17 is a cross-sectional view showing another example of the displaypanel PNL shown in FIG. 2.

FIG. 18 is a plan view schematically showing a touch detection device ofa mutual capacity system applied to the display device 1.

FIG. 19 is a plan view schematically showing a touch detection device ofa self-capacity system applied to the display device 1.

DETAILED DESCRIPTION

In general, according to one embodiment, a display device comprises afirst substrate, a second substrate opposing the first substrate, awiring substrate connected to the first substrate, a cover memberlocated on an opposite side to the first substrate so as to interposethe second substrate therebetween, and a conductive layer maintained ata predetermined potential, and the first substrate comprises anextension portion extending further from the second substrate, thewiring substrate is connected to the extension portion, the cover membercomprises a first surface opposing the extension portion, and theconductive layer overlaps the extension portion in plan view.

According to another embodiment, a display device comprises a firstsubstrate, a cover member opposing the first substrate, a wiringsubstrate connected to the first substrate and a conductive layermaintained at a predetermined potential, and the first substratecomprises an extension portion which connects the wiring substratethereto, the cover member comprises a first surface opposing theextension portion, and the conductive layer overlaps the extensionportion in plan view.

Embodiments will be described hereinafter with reference to theaccompanying drawings. The disclosure is merely an example, and properchanges within the spirit of the invention, which are easily conceivableby a skilled person, are included in the scope of the invention as amatter of course. In addition, in some cases, in order to make thedescription clearer, the widths, thicknesses, shapes, etc., of therespective parts are schematically illustrated in the drawings, comparedto the actual modes. However, the schematic illustration is merely anexample, and adds no restrictions to the interpretation of theinvention. Besides, in the specification and drawings, the same elementsas those described in connection with preceding drawings are denoted bylike reference numerals, and a detailed description thereof is omittedunless otherwise necessary.

In this embodiment, a display device comprising a touch detectionfunction will be described. The touch detection function, which will bediscussed here, is equivalent to detection of approaching or contactingof an object to be detected, with respect to the display device. Thedisplay device of this embodiment can be used in various devices such assmartphones, tablet terminals, mobile phones, notebook computers, andgame consoles. The main structure described in this embodiment isapplicable to a liquid crystal display device, a self-luminous displaydevice such as an organic electroluminescent display device, Micro LEDdisplay device, and an electronic paper display device comprising anelectrophoresis element, etc., a display device adoptingmicro-electromechanical systems (MEMS), and a display device adoptingelectrochromism.

FIG. 1 is a cross section schematically showing a display device 1according to this embodiment. In the figure, a first direction X and asecond direction Y are directions crossing each other, and a thirddirection Z is a direction crossing the first direction X and the seconddirection Y. For example, the first direction X, the second direction Yand the third direction Z are orthogonal to each other, but they maycross each other at an angle other than 90 degrees. The first directionX and the second direction Y correspond to a direction parallel to thesurface of the display, and the third direction Z correspond to athickness direction of the display device 1. In this specification, adirection indicated by the tip of the arrow along the third direction Zis referred to as upward (or simply, up), and a direction opposite tothat indicated by the tip of the arrow is referred to as downward (orsimply, down). Such expressions as “a second member on a first member”and “a second member below a first member” mean that the second membermay be in contact with the first member or may be apart from the firstmember. Further, when it is assumed that an observation position atwhich the display device 1 is to be observed is located at the pointingend side of the arrow indicating the third direction Z, a view toward anX-Y plane defined by the first direction X and the second direction Y isreferred to as a plan view.

The display device 1 comprises a display panel PNL, an illumination unitBL, a control substrate 2, a wiring substrate 31, a housing 4, a covermember 5 and the like.

Although the illustration thereof is omitted, the display device 1comprises a sensor which detects approaching or contacting of an objectto be detected, with respect to the display device 1, as will bedescribed later. This embodiment is applicable to even a device whichutilizes an exclusive touch panel independent of the display panel PNL,as the sensor, or a device which shares some of the parts with those ofthe display panel PNL.

The display panel PNL is, for example, an active-matrix liquid crystaldisplay panel. The display panel PNL comprises a first substrate SUB1, asecond substrate SUB2 and a liquid crystal layer LC (not shown) heldbetween the first substrate SUB1 and the second substrate SUB2. Forexample, the display panel PNL displays images by selectivelytransmitting light irradiated from the illumination unit BL.

The illumination unit BL is located under the display panel PNL. Theillumination unit BL comprises, for example, a light guide and a lightsource arranged along with an edge of the light guide.

The control substrate (control circuit board) 2 is located under theillumination unit BL, and is accommodated in the housing 4. On thecontrol substrate 2, an IC chip which controls the touch detectionfunction of the display device 1, a communication module for carryingout communications with the outside, a host device which controlsoperation of the display device 1 by various applications implementedtherein, and the like are mounted as will be described later. Note thatthe control substrate 2 may include an IC chip which controls thedisplay function of the display panel PNL.

The wiring substrate 31 electrically connects the display panel PNL andthe control substrate 2 to each other. For example, the wiring substrate31 is a flexible printed circuit board (FPC). In the exampleillustrated, one end portion of the wiring substrate 31 is provided onone end portion of first substrate SUB1, and the other end portion ofthe wiring substrate 31 is provided on one end portion of the controlsubstrate 2. Note that a part or entirety of each of the IC chip thatcontrols the touch detection function described above, and the IC chipwhich controls display function may be mounted in the wiring substrate31.

The cover member 5 is located on the display panel PNL. In the exampleillustrated, the cover member 5 covers the entire display panel PNL. Thecover member 5 is formed from, for example, a transparent material suchas glass or resin.

FIG. 2 is an enlarged view of a vicinity of the wiring substrate 31shown in FIG. 1. The display device 1 further comprises a driver 6, aconductive layer CL1 (shield conductive layer), a polarizer PL, andadhesive layers 71 and 72, in addition to the display panel PNL, theillumination unit BL, the control substrate 2, the wiring substrate 31and the cover member 5. Note that the housing 4 is not shown in FIG. 2.

In the display panel PNL, the first substrate SUB1 is larger than thesecond substrate SUB2. The first substrate SUB1 comprises an extensionportion EX extending from the second substrate SUB2. In the exampleillustrated, the extension portion EX extends along the second directionY.

The signal driver 6 is disposed on the extension portion EX. That is, inthe second direction Y, the signal driver 6 is located between an endportion E1 of the first substrate SUB1 and an end portion E2 of thesecond substrate SUB2. More specifically, the signal driver 6 isprovided on a side opposing the cover member 5 of the extension portionEX. The signal driver 6 controls the display operation of the displaypanel PNL.

The polarizer PL is located between the second substrate SUB2 and thecover member 5. The polarizer PL is adhered to the cover member 5 by theadhesive layer 71.

The control substrate 2 includes a host device 21, an IC chip 22, andthe like. The host device 21 in which, for example, various applicationsare implemented, controls the operation of the display device 1. The ICchip 22 controls, for example, the touch detection function of thedisplay panel PNL. The host device 21 and the IC chip 22 are provided ona surface opposite to a side opposing the illumination unit BL of thecontrol substrate 2. The control substrate 2 is adhered to the housingof the illumination unit BL by the adhesive layer 72. Alternatively, thecontrol substrate 2 is fixed with the illumination unit BL with a screwor the like, and the illumination unit BL is electrically connected to aground potential of the control substrate 2.

The cover member 5 comprises a first surface 5A opposing the displaypanel PNL and a second surface 5B on an opposite side to the firstsurface 5A. The cover member 5 overlaps the extension portion EXentirely along the third direction Z. In other words, the end portionE2, the end portion E1, and the end portion E5 of the cover member 5 arearranged along the second direction Y in this order.

In this embodiment, the conductive layer CL1 is provided on the firstside 5A and opposes at least the signal driver 6. In the exampleillustrated, the conductive layer CL1 overlaps the extension portion EXentirely along the third direction Z. Along the second direction Y, oneend portion of the conductive layer CL1 is located between the endportion E1 and the end portion E5. The other end portion of theconductive layer CL1 is in contact with the adhesive layer 71.

The conductive layer CL1 is a sheet-like member formed from, forexample, a metal material such as copper or aluminum. The conductivelayer CL1 may comprise an adhesive surface having adhesion and may beadhered to the first surface 5A using an adhesive. Alternatively, theconductive layer CL1 may be formed by, for example, applying a paste ofa conductive material containing a metal material such as silver. Inthis case, the conductive material may be applied directly to the firstsurface 5A, and the sheet-like member coated with the conductivematerial may be attached to the first surface 5A.

FIG. 3 is a plan view showing a configuration example of the displaydevice 1. FIG. 3 shows a plane parallel to the X-Y plane defined by thefirst direction X and the second direction Y.

The cover member 5 is, for example, a quadrangle and in the exampleillustrated, it is a rectangular shape whose length along the firstdirection X is greater than the length along the second direction Y. Inthe example illustrated, the end portion E5 extends along the firstdirection X.

The display panel PNL has substantially an identical shape to that ofthe cover member 5. That is, the display panel PNL is formed in arectangular shape whose length along the first direction X is greaterthan the length along the second direction Y. In plan view, the displaypanel PNL entirely overlaps the cover member 5. In the exampleillustrated, the end portion E2 and the end portion E1 extend along thefirst direction X. The first substrate SUB1 comprises end portions E1 aand E1 b extending along the second direction Y. The extension portionEX corresponds to a region between the end portion E1 and the endportion E2.

The display panel PNL includes a display area DA and a non-display areaNDA on an outer side of the display area DA. The display area DA islocated within a region where the first substrate SUB1 and the secondsubstrate SUB2 are superimposed on each other, and comprises a pluralityof pixels PX. The non-display area NDA surrounds the display area DA.

The display panel PNL comprises a plurality of scanning lines G, aplurality of signal lines S, and pixels PX in the display area DA. Thescanning lines G extend along the first direction X, and are arrangedalong the second direction Y at intervals. The signal lines S extendalong the second direction Y, and are arranged along the first directionat intervals. The pixels PX are each located in a vicinity of anintersection of a respective scanning line G and a respective signalline S, and contain a switching element, a pixel electrode and the like,as will be described later.

The scanning lines G and the signal lines S are lead out to theextension portion EX through the non-display area NDA, and areelectrically connected to the signal driver 6. In the exampleillustrated, the scanning line G lead out to an end portion E1 a side isconnected to a gate driver D1, and a scanning line G lead out to an endportion E1 b side is connected to a gate driver D2. The gate drivers D1and D2 are connected to the signal driver 6. Further, the signal lines Sare connected to the signal driver 6 through the end portion E1 side ofthe non-display area NDA. The signal driver 6 is electrically connectedto the host device 21 provided in the control substrate 2 via the wiringsubstrate 31. The signal driver 6 may be IC chip 22. In the exampleillustrated, the display device 1 comprises a wiring substrate 32 whichconnects the display panel PNL and the control substrate 2 to eachother. The wiring substrate 32 electrically connects the sensor, whichwill be described later, and the IC chip 22 to each other.

In this embodiment, the conductive layer CL1 is provided in a regionwhich overlaps at least a part of the signal driver 6 in plan view. Inthe example illustrated, the conductive layer CL1 overlaps the signaldriver 6 entirely. More specifically, the conductive layer CL1 overlapsthe extension portion EX, but does not overlap the second substrateSUB2. That is, the conductive layer CL1 is located in a region betweenthe end portion E2 and the end portion E5. In the example illustrated,the conductive layer CL1 is formed into a rectangular shapesubstantially, but it suffices if the conductive layer CL1 overlaps atleast the signal driver 6, and the shape thereof is not particularlylimited.

FIG. 4 is a plan view showing a configuration example of the pixels PXshown in FIG. 3. In the example illustrated, the pixels PX are eachdefined by each respective adjacent pair of scanning lines G arrangedalong the first direction Y and each respective adjacent pair of signallines S arranged along the second direction X.

The pixels PX each comprise a switching element SW and a pixel electrodePE. The switching element SW is, for example, a thin film transistor andis electrically connected to the respective scanning line G and therespective signal line S. More specifically, the switching element SWcomprises a gate electrode GE, a source electrode SE and a drainelectrode DE. The gate electrode GE is formed integrally with thescanning line G. In the example illustrated, the switching element SW isof a bottom gate type, in which the gate electrode GE is located underthe semiconductor layer SC, but it may be a top gate type in which thegate electrode GE is located above the semiconductor layer SC. Thesemiconductor layer SC is formed of, for example, amorphous silicon, butmay be formed of polycrystalline silicon or an oxide semiconductor. Thesource electrode SE is formed integrally with the signal line S, and isin contact with the semiconductor layer SC. The drain electrode DE isspaced from the source electrode SE and is in contact with thesemiconductor layer SC. The pixel electrode PE is superimposed on thedrain electrode DE, and is in contact with the drain electrode DE in thecontact hole CH.

FIG. 5 is a plan view showing a configuration example of a sensor SSprovided in the display device 1.

The sensor SS comprises a plurality of first electrodes Rx for detectingtouch operation, and a plurality of second electrodes Tx arranged so asto cross these first electrodes Rx. In the example illustrated, thefirst electrodes Rx each extend along the second direction Y and arearranged along the first direction X so as to be spaced apart from eachother. The second electrodes Tx each extend along the first direction X,and are arranged along the second direction Y so as to be spaced apartfrom each other. The first electrodes Rx and the second electrodes Txare disposed in a region which substantially overlaps the display areaDA in plan view. The first electrodes Rx are disposed on, for example,the second substrate SUB2. The second electrodes Rx are disposed on, forexample, the first substrate SUB1. When the second electrodes Tx aredisposed on the first substrate SUB1, the second electrodes Tx can beused as the common electrode of the display panel PNL.

The sensor SS comprises outer peripheral wiring lines connected to thefirst electrodes Rx and the second electrodes Tx, respectively. FIG. 5shows some of the outer peripheral wiring lines LRx connected to thefirst electrodes Rx. In the example illustrated, the outer peripheralwiring lines LRx are lead out to an end portion E2 side and areelectrically connected to the wiring substrate 32 through the extensionportion EX. The first electrodes Rx and the second electrodes Tx arecontrolled by the IC chip 22 mounted on the control substrate 2 throughthe wiring substrate 32.

The arrangement of the first electrodes Rx and the second electrodes Txis not limited to that of the example provided above. For example, bothof the first electrodes Rx and the second electrodes Tx may be disposedon the second substrate SUB2, or at least one side of the firstelectrodes Rx and the second electrodes Tx may be formed on, forexample, the first surface 5A of the cover member 5.

FIG. 6 is a perspective view showing an appearance of the display device1. FIG. 6 shows an opposite side to the display surface of the displaydevice 1, that is, a first surface 5A side of the cover member 5.

The illumination unit BL comprises a housing CHS which accommodates alight source, a light guide and the like. In this embodiment, theconductive layer CL1 is electrically connected to the housing CHS whichconstitutes the illumination unit BL. In the example illustrated, theconductive layer CL1 is connected to the housing CHS through aconductive layer CN (Lead-out conductive layer). More specifically, theconductive layer CN is disposed along an edge of the housing 4 and is incontact with conductive layer CL1 and the housing CHS. The conductivelayer CN may be formed from a material identical to or different fromthat of the conductive layer CL1. Note that the conductive layer CL1 andthe conductive layer CN may be formed integrally as one body. That is,the conductive layer CL1 may extend even to the illumination unit BL soas to be in contact with the case of the illumination unit BL.

The housing CHS is maintained at a reference potential. The referencepotential is, for example, the ground potential. In the exampleillustrated, the housing CHS is internally in contact with a referencepotential member RV maintained at, for example, the ground potential.For example, the reference potential member RV is fixed with a screw 81so as to be in contact with the housing CHS. Note that the method ofconnecting the reference potential member RV and the housing CHS to eachother is not limited to that of the example illustrated. For example,the reference potential member RV and the housing CHS may beelectrically connected through a conductive member 82.

The housing 4 is formed of, for example, a metal such as aluminum and isin contact with the housing CHS. For example, the housing 4 comprises anextension portion 4 a extending parallel to the main surface of thedisplay panel PNL. The extension portion 4 a is fixed to the housing CHSwith a screw 83 while in contact with the housing CHS. Thus, the housing4 can be set to the same potential to that of the housing CHS.Therefore, the control substrate 2 accommodated in the housing 4 canoperate without being interfered from outside.

Note that, for example, when the display device 1 is not a liquidcrystal display, the conductive layer CL1 does not need to be connectedto the housing CHS. The conductive layer CL1 may be connected to thereference potential member RV, for example, through a conductive member84. In the example illustrated, the conductive member 84 is in contactwith the conductive layer CN and the reference potential member RV.

FIG. 7 is a diagram showing another example of the appearance of thedisplay device 1. The example shown in FIG. 7 is different from that ofFIG. 6 in that the housing CHS and the reference potential member RV arenot connected through the screw 81 or the conductive member 82. In thiscase, the housing CHS is capacitively coupled with the referencepotential member RV.

According to this embodiment, the conductive layer CL1 is provided in aregion of the first surface 5A of the cover member 5, which overlaps atleast the signal driver 6 along the third direction Z. The conductivelayer CL1 is maintained at the ground potential. With this structure,even if voltage is applied to a second surface 5B side by staticdischarge or the like, it is possible to suppress adverse influence onthe operation of the signal driver 6, caused by the voltage, with thestructure shown in FIG. 2, for example, in which the conductive layerCL1 maintained at the ground potential is prepared in the region whichoverlaps the signal driver 6. Thus, even if voltage is applied to thesecond surface 5B, for example, flickering of images displayed on thedisplay panel PNL can be suppressed, thereby improving the displayquality of the display device 1.

Modified examples of the display device 1 will be described withreference to FIGS. 8 to 15.

FIG. 8 is a plan view showing the first modified example of the displaydevice 1. FIG. 9 is a perspective diagram showing an appearance of thedisplay device 1 of the first modified example. As shown in FIG. 8, thefirst modified example is different from that shown in FIG. 5 in thatthe conductive layer CL1 overlaps the outer peripheral wiring lines LRxof the sensor SS in plan view. In the example illustrated, theconductive layer CL1 extends along the first direction X in a regionbetween the end portion E2 and the end portion E5 in plan view. Theconductive layer CL1 overlaps the outer peripheral wiring lines LRx andthe wiring substrate 32 as well.

In the example illustrated, the single conductive layer CL1 overlapsboth of the signal driver 6 and the outer peripheral wiring lines LRx,but there may be separated Shield conductive layers which overlap thesignal driver 6 and the outer peripheral wiring lines LRx individually.For example, a first shield conductive layer overlaps the signal driver6, and a second shield conductive layer overlaps the outer peripheralwiring lines LRx. In this case, each of the conductive layers iselectrically connected to the housing CHS.

Further, in FIG. 9, the conductive layer CN may be provided on a wiringsubstrate 32 side of the conductive layer CL1, or may be on both sidesof the conductive layer CL1 while interposing the conductive layer CL1therebetween.

In the first modified example, advantages effect similar to those of theexample shown in FIG. 5 can be obtained. Further, according to the firstmodified example, the conductive layer CL1 overlaps part of the outerperipheral wiring lines LRx and a part of the wiring substrate 32. Withthis structure, entering of noise to the outer peripheral wiring linesLRx can be suppressed. Therefore, the display quality can be improvedand at the same time, the operation of the sensor SS can be stabilized.

FIG. 10 is a plan view showing the second modified example of thedisplay device 1. FIG. 11 is a perspective diagram showing an appearanceof the display device 1 of the second modified example. As shown in FIG.10, the second modified example is different from that shown in FIG. 5in that the conductive layer CL1 is disposed in a frame-like fashion.More specifically, the conductive layer CL1 is disposed over the entirenon-display area NDA. With such structure, the conductive layer CL1overlaps, in plan view, the scanning lines G and the signal lines S,which are lead out to the non-display area NDA, and the outer peripheralwiring lines LRx. In the example illustrated, the conductive layer CL1overlaps also the outer peripheral wiring lines LRx extending along theend portion E2. On the other hand, the conductive layer CL1 does notsubstantially overlap the first electrodes Rx or the second electrodesTx.

In the second modified example, advantages effect similar to those ofthe example shown in FIG. 5 can be obtained. Further, the region wherethe outer peripheral wiring lines LRx and the conductive layer CL1overlap each other is larger than that of the first modified example,and therefore the entering of noise to the outer peripheral wiring linesLRx can be further suppressed. Therefore, the display quality can beimproved and at the same time, the operation of the sensor SS can bestabilized.

FIG. 12 is a cross section showing the third modified example of thedisplay device 1. The third modified example is different from thatshown in FIG. 2 in that the conductive layer CL1 covers the wiringsubstrate 31. Along the second direction Y, the conductive layer CL1 isbrought into contact partially with the first surface 5A between the endportion E2 and the end portion E5, and also extends to below the controlsubstrate 2. That is, one end portion (first end portion) ECa of theconductive layer CL1 is in contact with the first surface 5A, andanother end portion (second end portion) ECb of the conductive layer CL1is located under the control substrate 2. The first substrate SUB1 andthe signal driver 6 are located between the one end portion ECa and theother end portion ECb along the third direction Z. The signal driver 6and the wiring substrate 31 are located in an inner region surrounded bythe conductive layer CL1.

FIG. 13 is a perspective diagram showing an appearance of the displaydevice 1 of the third modified example.

The wiring substrate 31 comprises wiring lines WL, films F1 and F2 eachformed from an insulating material, and reference potential members V1and V2 each formed from a conductive material. The reference potentialmembers V1 and V2 and the wiring lines WL are sandwiched between thefilm F1 and the film F2. The reference potential members V1 and V2 areat the same potential and both are fixed to the ground potential. Thewiring lines WL are located between the reference potential member V1and the reference potential member V2 and are electrically connected thefirst electrode Rx and the IC chip 22. In the example illustrated, thefilm F1 comprises a through hole HL1 to expose the reference potentialmember V1 and a through hole HL2 to expose the reference potentialmember V2.

The conductive layer CL1 is located on an outer side with respect to thewiring substrate 31, so as to cover the wiring substrate 31 to beenclosed therein. The conductive layer CL1 is in contact with thereference potential member V1 in the hole through HL1, and with thereference potential member V2 in the through hole HL2. Thus, theconductive layer CL1 is maintained at the same potential as that of thereference potential members V1 and V2, that is, the ground potential.

In the third modified example, advantages effect similar to those of theexample shown in FIG. 2 can be obtained. Further, the signal driver 6and the wiring substrate 31 are surrounded by the conductive layer CL1,and therefore it is possible to suppress the entering of noise from, forexample, the region between the cover member 5 and the first substrateSUB1 (that is, the side surface of the display panel) to the signaldriver 6. Moreover, the entering of noise to the wiring substrate 31 canbe suppressed. Consequently, flickering of images displayed can besuppressed, thereby improving the display quality of the display device1.

FIG. 14 is a cross section showing a fourth modified example of thedisplay device 1. The fourth modified example is different from thethird modified example in that the signal driver 6 is mounted on thewiring substrate 31. That is, the signal driver 6 is located between thewiring substrate 31 and the conductive layer CL1 along the thirddirection Z. In the example illustrated, an insulating layer IL isinterposed between the signal driver 6 and the conductive layer CL1. InFIG. 14, the insulating layer IL is provided on the upper surface of thesignal driver 6, but it may extend to a position exceeding the other endportion ECb of the conductive layer CL1. Moreover, the signal driver 6may be provided on the wiring substrate 31 and under the display panelPNL. The conductive layer CL1 is connected to the reference potentialmembers V1 and V2 as in the example shown in FIG. 13.

In this example, advantages effect similar to those of the thirdmodified example can be obtained. Further, with the insulating layer ILthus provided, contacting between the signal driver 6 and the conductivelayer CL1 can be prevented. Thus, short-circuiting between the signaldriver 6 and the conductive layer CL1 is prevented and the operation ofthe signal driver 6 can be stabilized. Consequently, the display qualityof the display device 1 can be improved.

FIG. 15 is a cross section showing a fifth modified example of thedisplay device 1. The fifth modified example is different from theexample shown in FIG. 2 in that the display device 1 further comprises aconductive layer CL2. The conductive layer CL2 is in contact with theconductive layer CL1 and extends to below the control substrate 2. Thatis, one end portion ECc of the conductive layer CL2 is in contact withthe conductive layer CL1, and another end portion ECd of the conductivelayer CL2 is located below the control substrate 2. The first substrateSUB1 and the signal driver 6 are located between the one end portion ECcand the other end portion ECd along the third direction Z. The signaldriver 6 and the wiring substrate 31 are located within an inner regionsurrounded by the conductive layer CL1 and the conductive layer CL2.

As in the case of the example shown in FIG. 6 or 7, the conductive layerCL1 is electrically connected to the housing CHS of the illuminationunit BL. The conductive layer CL2 may be electrically connected to thereference potential members V1 and V2 of the wiring substrate 31 as inthe example shown in FIG. 13. Further, the signal driver 6 may bemounted on the wiring substrate 31 as in the fourth modified example. Inthe fifth example, advantages effect similar to those of the thirdmodified example can be obtained.

FIG. 16 is a cross section showing a sixth modified example of thedisplay device 1. The sixth modified example is different from theexample shown in FIG. 2 in that an insulating layer IL is providedbetween the signal driver 6 and the conductive layer CL1. As in theexample shown in FIG. 6 or 7, the conductive layer CL1 is electricallyconnected to the housing CHS of the illumination unit BL.

The insulating layer IL overlaps at least the entire driver 6 along thethird direction Z. In the example illustrated, the insulating layer ILis in contact with the conductive layer CL1. The insulating layer IL hassubstantially the same size that of the conductive layer CL1 andoverlaps the extension portion EX as well.

In the sixth modified example, advantages effect similar to those of theexample shown in FIG. 2 can be obtained. Further, according to the sixthmodified example, contacting between the signal driver 6 and theconductive layer CL1 can be prevented. Thus, short-circuiting betweenthe signal driver 6 and the conductive layer CL1 is prevented and theoperation of the signal driver 6 can be stabilized. Consequently, thedisplay quality of the display device 1 can be improved.

FIG. 17 is a cross-sectional view showing another configuration exampleof the display panel PNL shown in FIG. 2. The example shown in FIG. 17is different from that shown in FIG. 2 in that the display panel PNLcomprises an organic EL device as the display element. The otherstructures of the display device 1 are similar to those of FIGS. 2, 3, 5to 16, 18, and 19.

The display panel PNL comprises an insulating substrate 10, first tofifth insulating films 11 to 15, a reflective layer RL, an organic ELdevice OLED, a sealing film 16, a wiring line L, terminals T11 and T12,etc.

For example, the insulating substrate 10 is formed from an organicinsulating material such as polyimide. The insulating substrate 10 maybe formed from a transparent insulating material such as resin or glass.The first to fourth insulating films 11 to 14 are stacked on theinsulating substrate 10 in this order. Although the details will beomitted, a semiconductor layer of the switching element for driving theorganic EL device OLED is formed on the first insulating film 11, a gateelectrode is formed on the second insulating film 12, and a sourceelectrode and a drain electrode are formed on the third insulating film13. The first to third insulating films 11 to 13 are each formed from,for example, an inorganic insulating material such as silicon oxide,silicon nitride or silicon oxynitride. The fourth insulating film 14 isformed from an organic insulating material.

The organic EL device OLED is formed on the fourth insulating film 14.In the example illustrated, the organic EL device OLED is of theso-called top emission type, which emits light to an opposite side tothe insulating substrate 10, but the type is not limited to that of thisexample. It may be of the so-called bottom emission type, which emitslight to the insulating substrate 10 side. The organic EL device OLEDcomprises a pixel electrode PE, a common electrode CE and an organicemitting layer ORG.

A pixel electrode PE is provided on the fourth insulating film 14. Thepixel electrode PE functions as, for example, a positive electrode ofthe organic EL device OLED. The pixel electrode PE is electricallyconnected to the switching element (not shown). The organic emittinglayer ORG is formed on the pixel electrode PE. The organic emittinglayer ORG may further comprise an electron-injection layer, ahole-injection layer, an electron-transport layer, a hole-transportlayer and the like, to improve light-emission efficiency. The commonelectrode CE is formed on the organic emitting layer ORG. The commonelectrode CE functions as, for example, a negative electrode of theorganic EL device OLED. The common electrode CE and the pixel electrodesPE are formed from, for example, a transparent conductive material suchas indium-tin-oxide (ITO) or indium-zinc-oxide (IZO). The organicemitting layer ORG emits light at the brightness according to voltage(or current) applied between the pixel electrode PE and the commonelectrode CE.

In the case of a top emission type, as shown in FIG. 17, the organic ELdevice OLED should preferably include a reflective layer RL between thefourth insulating film 14 and the pixel electrode PE. The reflectivelayer RL is formed from, for example, a highly reflective metal materialsuch as aluminum or silver.

The organic EL device OLED of each pixel PX is formed by partition withfifth insulating films (ribs) 15 of an organic insulating material. Inthe example illustrated, the common electrode CE is in contact with theorganic emitting layer ORG and also with the fifth insulating film 15.

The sealing film 16 covers the organic EL device OLED. The sealing film16 inhibits the entering of moisture or oxygen to the organic EL deviceOLED, thereby suppressing degradation of the organic EL device OLED. Forexample, the sealing film 16 comprises a first inorganic film 161, anorganic layer 162 and a second inorganic film 163. The first inorganicfilm 161 is formed on the organic EL device OLED. In the exampleillustrated, the first inorganic film 161 is in contact with the commonelectrode CE. The second inorganic film 163 is located above the firstinorganic film 161. The organic layer 162 is located between the firstinorganic film 161 and the second inorganic film 163 and is in contactwith these films.

In this example, the structure from the insulating substrate 10 to thecommon electrode CE is equivalent to the first substrate SUB1 shown inFIG. 2. The sealing film 16 is equivalent to the second substrate SUB2shown in FIG. 2. That is, the extension portion EX in this example isequivalent to a portion of the display panel PNL, which extends furtherfrom the sealing film 16. The entirety of each of the fourth insulatingfilm 14 and the fifth insulating film 15 overlaps the sealing film 16along the third direction Z. On the other hand, the insulating substrate10 and the first to third insulating films 11 to 13 extend further fromthe sealing film 16 along the second direction Y, so as to form theextension portion EX.

The wiring line L is formed on the third insulating film 13. One end ofthe wiring line L is covered by the fourth insulating film 14, whereasthe other end of the wiring line L is located in the extension portionEX. A terminal T11 is formed on the fourth insulating film 14. Theterminal T11 passes through the contact hole CH formed in the fourthinsulating film 14, so as to be in contact with the wiring line L. Thecommon electrode CE extends to an extension portion EX side with respectto the organic EL device OLED, and is in contact with the terminal T11.Thus, the wiring line L and the organic EL device OLED are electricallyconnected to each other. A terminal T12 is formed on the other end sideof the wiring line L. The signal driver 6 described above is connectedto, for example, the terminal T12. If needed, a protective film may beformed to cover the wiring line L.

FIG. 18 is a plan view schematically showing a mutual-capacitive touchdetection device 200 to be applied to the display device 1.

The touch detection device 200 comprises a sensor SS and an IC chip 22.As mentioned before, the sensor SS comprises second electrodes Tx (Tx1,Tx2, Tx3, . . . ) as drive electrodes, and first electrodes Rx (Rx1,Rx2, Rx3, . . . ) as detection electrodes, insulated from the secondelectrodes Tx and arranged so as to cross the second electrodes Tx. Ateach of the intersections between the second electrodes Tx and the firstelectrode Rx, a capacitance is formed.

In the display panel PNL, the common electrode to which a certainpotential is applied during a display period may be utilized as thesecond electrodes Tx described above. To explain, in the so-calledin-cell type display device, the second electrodes Tx (Tx1, Tx2, Tx3, .. . ) are used as a common electrode for the pixel circuits during adisplay period. In the so-called on-cell type display device, the secondelectrodes Tx and the first electrodes Rx are provided as electrodesexclusively used for touch detection on the touch panel (touch detectionsubstrate) provided for touch detection. The touch detection device 200is controlled by the IC chip 22.

The touch detection period is set, for example, dispersedly in oneframe. Therefore, in the display device, the display period and thetouch detection period are time-shared. A selector SELA suppliespulse-like drive signals Txs sequentially to the second electrodes Tx1,Tx2, Tx3, . . . , respectively during the touch detection period. If afinger of the user is in contact (touching) with a certain region,detection signals Rxs output from detection electrodes in an applicabletouched location become lower in level than detection signals Rxs outputfrom other detection electrodes. The figure illustrates the case wherethe level of the detection signals when not detecting a touch is AP1 andthe case where the level of the detection signals of the electrodesdetecting a touch is AP2 (<AP1).

FIG. 19 is a plan view schematically showing a self-capacitive touchdetection device 200 to be applied to the display device 1. The touchdetection device 200 comprises a sensor SS, an IC chip 22 and adrive-detect circuit DDET. In the self-capacitive type, the sensor SScomprises a plurality of common electrodes CE (CE11, CE12, CE13, . . . ,CE21, CE22, CE23, . . . , CE31, CE32, CE33, . . . ) arranged, forexample, in a matrix for detecting touch operations. To the commonelectrodes CE, outer peripheral wiring lines TR (TR1, TR2, . . . ) areconnected, respectively. The outer peripheral wiring lines TR areconnected to a drive-detect circuit DDET. The drive-detect circuit DDETis formed, for example, in the non-display area NDA of the firstsubstrate (array substrate) SUB1 of the display panel PNL. Thedrive-detect circuit DDET is controlled by the IC chip 22, so as tocontrol the touch detection function. Note that the area of one commonelectrode CE is, for example, about 24 times of that of one pixelregion.

The above-provided description is directed to an example in which thecommon electrodes CE arranged in a matrix are used as electrodes of theself-capacitive type, but each of the first electrodes Rx and the secondelectrodes Tx shown in FIG. 18 may be used as a self-capacitiveelectrode. For example, the touch detection device 200 may use only thesecond electrodes Tx or only the first electrodes Rx to operate as theself-capacitive type. Such operation is performed, for example, in apower saving mode. The first electrodes Rx shown in FIG. 5, 8 or 10 maybe used for a self-capacitive electrode detection. The first electrodesRx may be arranged in a matrix on the second substrate SUB2, and thefirst electrodes Rx may be controlled by the IC chip 22 via theperipheral wiring lines LRx and the wiring substrate 32. The IC chip 22may be disposed on the wiring substrate 32 or built in the signal driver6. In this case, the sensor SS may use only the first electrodes Rx soas to operate as the self-capacitive type.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A display device comprising: a first substrate; asecond substrate opposing the first substrate; a wiring substrateconnected to the first substrate; a cover member located on an oppositeside to the first substrate so as to interpose the second substratetherebetween; and a conductive layer maintained at a predeterminedpotential, the first substrate comprising an extension portion extendingfurther from the second substrate, the wiring substrate being connectedto the extension portion, the cover member comprising a first surfaceopposing the extension portion, the conductive layer overlapping theextension portion in plan view and comprising a first end portion incontact with the first surface and a second end portion on an oppositeside to the first end portion, and the first substrate being locatedbetween the first end portion and the second end portion.
 2. The displaydevice of claim 1, further comprising: a driver provided in theextension portion, wherein the conductive layer overlaps the driver atleast partially in plan view.
 3. The display device of claim 2, whereinthe conductive layer overlaps the driver entirely in plan view.
 4. Thedisplay device of claim 2, further comprising: an insulating layerlocated between the driver and the conductive layer.
 5. The displaydevice of claim 1, wherein the conductive layer covers the wiringsubstrate.
 6. The display device of claim 1, wherein the wiringsubstrate further comprises a reference potential member, and theconductive layer is in contact with the reference potential member. 7.The display device of claim 1, further comprising: an adhesive layerlocated between the second substrate and the cover member, wherein theconductive layer is in contact with the adhesive layer.
 8. The displaydevice of claim 1, further comprising: an illumination unit accommodatedin a housing, wherein the illumination unit is located on an oppositeside to the second substrate so as to interpose the first substratetherebetween, the housing is at a reference potential, and theconductive layer is electrically connected to the housing.
 9. Thedisplay device of claim 1, further comprising: a sensor comprising adetection electrode and an outer peripheral wiring line electricallyconnected to the detection electrode, wherein the conductive layeroverlaps the outer peripheral wiring line at least partially in planview.
 10. A display device comprising: an illumination unit; a firstsubstrate; a cover member opposing the first substrate; and a conductivelayer maintained at a predetermined potential, wherein the conductivelayer comprises a first end portion connected to the cover member and asecond end portion on an opposite side to the first end portion, thefirst substrate is located between the first end portion and the secondend portion, the display device comprises a display area, the covermember entirely overlaps the display area in plan view, and a topportion of the illumination unit is coplanar with a top surface of thefirst substrate.
 11. The display device of claim 10, wherein the firstsubstrate includes an extension portion, and the cover member includes afirst surface opposing the extension portion.
 12. The display device ofclaim 11, further comprising: a driver provided in the extensionportion, wherein the conductive layer overlaps the driver at leastpartially in plan view.
 13. The display device of claim 12, wherein theconductive layer overlaps the driver entirely in plan view.
 14. Thedisplay device of claim 12, further comprising: an insulating layerlocated between the driver and the conductive layer.
 15. The displaydevice of claim 14, wherein the driver is included in an IC chip, theinsulating layer is connected to the IC chip.
 16. The display device ofclaim 11, further comprising: a wiring substrate connected to the firstsubstrate, wherein the conductive layer covers the wiring substrate. 17.The display device of claim 16, wherein the wiring substrate furthercomprises a reference potential member, and the conductive layer isconnected to the reference potential member.
 18. The display device ofclaim 10, further comprising: a housing supplied with a referencepotential, wherein the conductive layer is electrically connected to thehousing.
 19. The display device of claim 10, further comprising: adetection electrode; and a wiring line coupled to the detectionelectrode, wherein the conductive layer is located between the wiringline and the cover member.
 20. The display device of claim 10, furthercomprising: a driver provided on the first substrate; a detectionelectrode; and a wiring line coupled to the detection electrode; whereinthe conductive layer is located between the cover member, and each ofthe driver and the wiring line.